A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateFast, Reliable ADU Builders Across Home Gardens
Adding an ADU in Home Gardens usually costs between $180,000 and $320,000 for a detached unit, with garage conversions running $120,000 to $210,000. The single biggest factor here isn’t square footage. It’s whether your lot passes a county percolation test and whether your 1960s ranch has wiring that meets today’s code once we open the wall. We’re Lodgewick ADU Riverside, and we work on Home Gardens properties every week. Call (831) 292-4191 and a live person answers, day or night.
This page is written for homeowners in Home Gardens specifically, because building an accessory dwelling unit in unincorporated Riverside County is not the same as building one in Corona or Riverside. The permit path is slower. The septic rules are stricter. And the homes we open up, mostly 1950s-to-1970s stucco ranches on 7,200-plus square foot lots, hide things that change your budget. We’ll walk through all of it, with real numbers.
Why Lodgewick ADU Riverside Is Home Gardens’s Preferred ADU Builders Company
Home Gardens homeowners call us because we put the price in writing before we start, and we name exactly what the guarantee covers. That’s The Kingswell Guarantee: written price first, a defined arrival window, a clean job site, and a written guarantee on every project. If something isn’t right within 365 days, we come back and fix it. Free. That’s the 365-Day Done Right Promise, and it’s on paper before the first nail goes in.
Our ADU Builders team knows the difference between what Riverside’s building department approves quickly and what unincorporated Riverside County sends back with correction notices. That local knowledge keeps a Home Gardens project from stalling for weeks while you chase a county permit clerk. We coordinate dispatch from the brand’s Inland Empire office, but the crews you’ll see on your property are background-checked, uniformed, and local to Home Gardens.
Russ Delmar leads the work here. He’s walked more Home Gardens lots than we can count, and he’ll tell you straight if a detached ADU makes sense on your septic system or if a garage conversion is the smarter play. That’s how we build trust: straight answers, written commitments, no surprises at the door.
ADU Construction in Home Gardens
ADU construction in Home Gardens means building a fully permitted accessory dwelling unit on a lot that was originally platted for one single-family ranch home, usually on septic. The big variable here is not labor or materials; it’s what the county makes you prove before the permit gets issued. We handle that process end to end: perc testing, septic review, county submittal, and the build itself. A full ADU construction project in Home Gardens typically lands between $180,000 and $320,000 depending on size, finish level, and what the lot requires.
County Permits and Septic Reality
Because much of Home Gardens lacks sewer lines, ADU construction often hinges on a percolation test and a septic tank upgrade. If the drain field fails, you’re looking at $20,000 to $35,000 in additional work before the ADU can be approved. We don’t quote a fixed price without knowing that answer first.
Code Upgrades Once Walls Open
Older Home Gardens homes frequently have deteriorated romex, undersized circuits, or previous unpermitted work hiding behind drywall. When we open a wall for a new electrical tie-in, the county requires us to bring what we touch up to current code. We build allowances for that into the written contract so the price doesn’t move on you after demo starts.
Detached ADU in Home Gardens
A detached ADU in Home Gardens is a stand-alone small house built in the rear yard of your existing property, and it’s the most popular option here because the lots are big enough to hold one. Most Home Gardens ranch homes sit on 7,200 square feet or more, which leaves real room behind the garage. A detached ADU in Home Gardens typically runs $200,000 to $320,000 for a one-bedroom unit with a kitchenette and full bath.
Why Detached Wins on These Lots
Detached units keep the original home untouched, which matters when the main house has older wiring or previous unpermitted modifications. You don’t trigger upgrades inside the existing structure, and you get rental separation that many Home Gardens owners want. With renters commuting to Riverside and Corona, a detached ADU here can command strong monthly rent.
Septic Limits and Placement
On Home Gardens lots without sewer, the county limits the ADU’s size and placement based on the septic system’s rated capacity. We often recommend a one-bedroom or studio footprint to stay within what your existing tank can handle. That’s a conversation we have early, before drawings begin.
Trusted Brands We Service in Home Gardens
We work with leading prefab and panelized systems, including Abodu, Cover, and Dvele, and we match the right system to your lot, budget, and timeline. For Home Gardens specifically, prefab can compress the timeline once permits clear, which matters when county review already adds weeks. We stock what these systems need locally, so a missing connector or trim piece doesn’t stall your project for a week waiting on freight. If you already own a prefab unit or you’re comparing manufacturers, we can install it and handle the site work, foundation, and utility tie-ins under the same written contract.
Common ADU Builders Problems We See in Home Gardens Homes
- Failed perc tests killing a fixed quote. A builder quotes a price without running a percolation test, then the drain field fails and the septic tank has to be replaced for $20,000-plus. We run the test first, and any septic work goes into the written price before you sign.
- Unpermitted past remodels surfacing at inspection. A Home Gardens home from the 1960s often had a room added or a panel swapped without county sign-off. When the inspector comes for the ADU permit, they flag it, and now you’re fixing old problems before building new square footage.
- Deteriorated wiring hidden in stucco walls. Opening a 1970s exterior wall for a subpanel tie-in regularly reveals romex with cracked sheathing or undersized 14-gauge wire on a 20-amp circuit. We write an electrical allowance into every Home Gardens contract because we expect to find it.
- Moisture-swollen framing around old vents. Laundry vents and bath fans from the 1950s and 60s leak inside the wall cavity for decades. When we sister studs or reframe, that’s priced and approved in writing before we cut anything, not sprung on you as a change order.
Pricing for ADU Builders in Home Gardens, CA
A garage conversion in Home Gardens runs $120,000 to $210,000. A detached studio ADU runs $180,000 to $260,000, and a one-bedroom detached unit runs $200,000 to $320,000. A junior ADU built inside the existing home footprint runs $90,000 to $150,000. What moves the number here: septic upgrades if your lot fails perc, the age of your home’s electrical panel, and whether the county requires fire sprinklers or additional parking. We give you a written line-item price before any work starts, and that price includes defined allowances for what we find when walls open. Call (831) 292-4191 for a free estimate, and we’ll walk your lot and give you real numbers, not a range pulled from a website.
Key Takeaways
- Home Gardens is unincorporated Riverside County, so permits take longer and septic rules are stricter than nearby cities.
- Most lots here are 7,200 sq ft or larger, which makes detached ADUs feasible.
- Percolation tests and septic capacity often decide whether an ADU gets built at all.
- Written allowances for electrical and framing surprises are standard in our contracts here.
We Also Serve Cities Near Home Gardens
If you’re in Riverside, Ontario, Fontana, or Chino, we bring the same written-price approach and the same 365-Day Done Right Promise to your project. Home Gardens is central to our Inland Empire service area, and we’re regularly out here for estimates and builds. For more about our work across the region, see Home Gardens and the surrounding communities we serve.
Serving Home Gardens, CA - Our Local Coverage Area
We’re based in the Home Gardens area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About ADU Builders in Home Gardens
A percolation test measures how fast water drains through your soil, and Home Gardens requires it because most of the area lacks sewer lines and the county must confirm your septic system can handle the added bathroom and kitchen wastewater. If your lot fails, you’ll need a new or enlarged septic tank and possibly a replacement drain field, which typically adds $20,000 to $35,000 and can shift where the ADU can be placed. We run this test before we quote a fixed price, so you know the real number up front. Call (831) 292-4191 and we’ll schedule the test and walk you through the results.
Any portion of the main house we open for the ADU’s electrical tie-in must be brought up to current Riverside County code before the inspector signs off, which commonly means replacing deteriorated romex, adding AFCI/GFCI breakers, and correcting undersized circuits. The exact upgrades depend on what’s inside your walls and what the inspector flags, so we write an electrical allowance into your contract rather than pretending the original wiring is fine. On a recent Vintage Lane project, we found 14-gauge wiring on a 20-amp circuit and moisture-swollen framing around a laundry vent; both were priced and approved in writing before we cut anything. Call (831) 292-4191 to get a written estimate that accounts for what your home actually has.
Yes, a partial garage conversion is one of the most cost-effective ADU paths in Home Gardens, and you can often keep a storage bay while converting the rest, as long as the added bathroom and kitchen stay within your septic system’s rated capacity. The county will review the converted square footage against your existing tank size, so a three-quarter bath and modest kitchenette usually fit better than a full two-bath layout. We’ve done exactly this on multiple Home Gardens ranch lots, and the written price covers the conversion, the seismic framing, and the utility work. Call (831) 292-4191 and we’ll look at your garage and your septic records together.
Home Gardens’ inland climate pushes us toward high-efficiency HVAC, cool-roof materials, and insulation packages designed for sustained heat, because a poorly insulated ADU here becomes unusable from June through September. We spec minimum R-21 walls and R-38 ceilings on detached units, and we recommend cool-roof shingles or reflective roofing that reduce heat gain more than standard asphalt. Mild winters mean we don’t have to over-build for cold, but the summer heat is the real design driver. Call (831) 292-4191 and we’ll show you the insulation and HVAC specs we use on Home Gardens builds.
Start by telling your ADU builder up front, because the county inspector will discover the unpermitted work during the ADU review and flag it on the same correction notice, which can stall your project for weeks. We document what exists, determine what the county will require you to correct, and price those corrections in writing before the ADU permit is submitted. You won’t be the first Home Gardens owner we’ve helped through this, and you won’t be the last. Call (831) 292-4191 and we’ll review your property’s permit history with you and map out a realistic plan.
Written by Russ Delmar, Owner at Lodgewick ADU Riverside, serving Home Gardens and the surrounding Inland Empire communities.
